Updating C++ Interop documentation

[Mehdi]

Hi D community,

I just wanted to say that I'm a huge fan of the D language, and I 
think you guys are doing awesome work. Recently, I've been 
exploring interoperability with C++, and it has been a great 
learning experience. However, I believe the documentation on this 
page is incomplete and sometimes misrepresents what is possible.

To stay updated on the recent D language status regarding 
interop, I watched a d conf video on youtube: 
"https://www.youtube.com/watch?v=mI6-PmZy-u0&t=2279s". I've also 
been reading the repository that was discussed in the conference: 
"https://github.com/bosagora/agora".

I've also been studying the Druntime code, particularly the 
stdcpp library: 
"https://github.com/dlang/dmd/tree/master/druntime/src/core/stdcpp". There are also useful tests located in the Druntime repository. However, I feel like the documentation for interfacing with C++ code does not mention the capabilities of the core.stdcpp module and lacks examples of how to use it. I understand that writing documentation takes time, and you guys are busy, but if there is a to-do list somewhere, please consider adding "update docs interfacing with C++" to it.

Thank you for your hard work!